Thief tube



NOV. 15,1938. J BLAKE 2,137,128

THIEF TUBE Filed Ndv. 4,1956

2 Sheets-She et lv as (A 31 Z 6 I -Hg 4 28 a 15 I 13 17 m i/vzs FBLa/(,16 .ZECf/PWZI; v ,2 Jim/03. 5419415; w. 8 L 6 Ere-supra WAS .Nov. 15,1938. J. F. BLAKE THIEF TUBE Filed Nov. 4, 1956 2 Sheets-Sheet 2 s III 21 W55 W 2 4 3 MHz u w 71W: L M I a 5 f. z E3 1 5 Z3 Z1 n; 1 J w Ct 4 3 71 6 o 7 8 2 a 1 w 1. 22 1 4 3 /2 a 0 z 9 8 9 2 2 m 22 llllll 3 4 78 4 2Patented Nov. 15, 1938 THIEF TUBE James F. Blake, deceased, by Anna B.Blake,

Tulsa, kla., executrix; Anna. B- signee by decree of court lake, as-

Application November 4, 1936, Serial No. 109,160

3 Claims.

This invention relates to improvements in thief tubes of the typecomprising a tube or receptacle with a movable bottom closure, andemployed for taking samples of liquids fromstorage tanks and othercontainers at different depths within the liquid.

Objects of the invention are to providean improved thief tube ofthe'general type referred to; toprovide an improved construction ofbottom closure and supporting means therefor that will provide for theautomatic adjustment of the closure to the end seat or face of the tubeor receptacle and insure a tight fit between the parts and a liquidtight closure of the bottom of the tube or receptacle; to provideimproved latch mechanism for holding the closure locked in openposition, and improved means for automatically forcing the closure toclosed position when the latch mechanism is tripped, whereby a simple,eflicient, compact, satisfactory device is afforded.

The invention, with other objects and advantages thereof and theparticular construction, combinations and arrangements'of partscomprising the same,- will be understood from the hereinafter containeddetailed description when considered in connection with the accompanyingdrawings forming part hereof and illustrating one embodiment of theinvention.-

In the drawings; a. g I V Figure l is a side elevation of a thief tubeconstructed in accordance with the present inven-- tion, the lowerportion of the tube or receptacle being shown in section and the bottomclosure being shown locked in open position.

Fig. 2 is a side elevation and part section, the bottom closure beingshown in closed position.

Fig. 3 is a side elevation of the lower part of the-device with thebottom closure in closed position.

Fig. 4 is a front elevation.

Fig. 5 is a rear elevation.

Fig. 6 is a transverse section on the line 66 of Figure 2.

Fig. 7 is a top plan view of the closure.

Fig. 8 is a transverse section on the line 8--8 of Figure '7, the lowerend portions of the supporting arms for the closure being shown in sideelevation.

While a specific embodiment of the invention is illustrated in thedrawings, it will be understood that minor changes and modifications maybe made in the particular construction shown, and the invention may beembodied in other forms as will appeal to those skilled in the art andfalling within the scope of the appended claims, without departing fromthe spirit of the invention.

Referring to a detailed description of the particular embodiment of theinvention illustrated in the drawings, I designates a tube or receptacleopen at each end, and 2 is the closure for the bottom of the tube orreceptacle, the latter being shown as cylindrical and the closure beingcorrespondingly circular in shape.

-The closure 2 is supported'for swinging movement substantially edgewisetransversely of the bottom of the tube or receptacle by a pair of armsor levers 3 pivotally connected intermediate their ends to the tube orreceptacle at opposite sides thereof. The arms or levers 3 are mountedon trunnions 4, which as shown, may conveniently take the form of shortscrews engaging threaded openings in the, walls of the tube orreceptacle. The closure is mounted on the lower end portions of the armsor levers for limited play or rocking movement relatively thereto. Thelower end portions 5 of the arms or levers, which are reduced in sizeand rounded in cross section, extend through openings 6 in lugs lprojecting laterally from opposite side marginal portions of theclosure, said openings being slightly larger in diameter than thereduced end portions 5 of the arms or levers. The reduced end portions 5are threaded for a portion of their length, to receive jam nuts 8 uponwhich the lugs 'l of the closure rest. The tube or receptacle isprovided with a smooth, plain bottom face or seat 9 extending at aslight upward inclination from front to rear thereof,v as shown, theclosure 2 having a smoothly ground flat angular face or seat 2 and thetrunnions 4 for the arms or levers 3 are located substantially midwayopposite sides of the tube or receptacle. The upper ends of the arms orlevers 3 are attached to opposite ends of a coiled extension spring l0stretched circumferentially around the rear side of the tube orreceptacle, the spring having eyes at its ends engaging laterallyprojecting lugs II on the arms or levers and being under constanttension to draw the upper ends of the arms or levers toward the rearside of the tube or receptacle and move the closure to closed position.

As will be understood, the nuts 8 are adjusted so that the closure hassufficient play or rocking movement relatively to the arms or levers 3to enable it to automatically adjust itself to closely fit against thebottom face 9 of the tube or receptacle when the arms or levers areswung to move the closure to closed position, and the tension of thespring I0 transmitted through the arms or levers forces the closure tobecome tightly wedged between the inclined bottom face or seat 9 of thetube or receptacle and the jam nuts 8, and thus a secure liquid tightclosure for the tube or receptacle is provided.

A lever I2 is provided for prying the closure loose from the bottom faceor seat 9, said lever being fulcrumed near one end on a pin l3 supportedin lugs l4 projecting from the rear side of the tube or receptacle nearthe base thereof. applying pressure, conveniently by the thumb of theoperator, against the face [5 of the lever, the heel N5 of the same willbe forced against a lip IT on the closure and the closure will be movedrearwardly.

Supported for longitudinal sliding movement in bearings I8 and IS on thefront side of the tube or receptacle is a rod 20 and fixed on this rodis a latch member adapted to engage the arms or levers 3 and hold thebottom closure locked in open position as illustrated in Figure l of thedrawings. The latch member, which is of general arcuate shape, has acentral sleeve part 2! to engage the rod 29, and enlarged end portions22 that have shoulders 23 and curved front surfaces 24 to cooperate withshoulders 25 and curved surfaces 26 on the upper ends of the arms orlovers 3.

The inner faces of the central sleeve part 2! and the enlarged endportions 22 of the latch member are formed, as shown, to slidably engagethe wall of the tube or receptacle. The latch member, which isadjustably secured on the rod 20 by a set screw 27 on the sleeve part2|, is adapted to abut against the upper end of the bearing l8 and limitthe extent of downward travel of the rod. A stop collar 28 adjustablysecured on the rod 20 between the bearings 18 and I9 by a set screw 23,is adapted to engage the lower end of the bearing i8 and limit theupward travel of the rod. To look the closure in open position, thesame, after being pried loose from the seat 9 on the tube or receptacle,is drawn backwardly and upwardly until the curved surfaces 26 on theupper ends of the arms or levers 3 come in contact with the curvedsurfaces 24 on the end portions of the latch member, and by cam actionforce the latch member upwardly and then allow it to fall back so thatthe shoulders 23 on the latch member engage the shoulders 25 on theupper ends of the arms or levers. Stop lugs 33 on the walls of the tubeor receptacle, may be, and preferably are provided to limit the movementof the arms or levers in setting the closure in open position.

As will be understood the tension in the spring l3 maintains theshoulders 23 of the latch member in engagement with the shoulders 25 onthe arms or levers, and the closure is thus held in open position untilthe latch member is raised.

The rod is adapted to be adjusted as illustrated in Figure 1 of thedrawings to extend beyond the lower end of the tube or receptacle toautomatically trip the latch by engaging the bottom of a tank or thelike. The latch member may also be tripped manually through the mediumof a chain or cable 3| connected to a ring 32 thereon.

Pivotally connected to the upper end of the receptacle is a bail 33 towhich is attached a chain or cable 34 by which the device is loweredinto and withdrawn from the liquid. On the upper part of the tube orreceptacle is also a hook 35 to provide for hanging the device to someobject when it is inconvenient to use the bail 33 for that purpose.

In the use of the device, the trip rod 20 is adjusted to the latchmember and stop collar 28 so that the lower end of the trip rod is atthe predetermined distance below the lower end of the tube or receptaclewhen the stop collar 28 abuts against the bearing I8 and the latchmember is just high enough to release the arms or levers. The bottomclosure 2 is then set to open position as hereinbefore described. Thedevice is then lowered into the tank or cask of liquid by means of thechain or cable 34 attached to the bail 33. As the thief tube sinks, aperfect core of the liquid passes relatively upward through theunrestricted opening at the lower end of the tube or receptacle andthence on through the tube or receptacle, this core within the tube orreceptacle is therefore a true section of the stratum of the liquid atthe depth of the thief tube.

When the lower end of the trip rod 20 engages the bottom of the tank,cask or other container, the tube or receptacle continues to sink,thereby causing the trip rod to push the latch member upwardly clear ofthe arms or levers 3 and allowing the spring I!) to quickly draw theupper ends of the arms or levers backwardly to swing and wedge theclosure to a tightly closed position as illustrated in Figure 2 of thedrawings.

Samples of liquid can also be taken at various depths by pullingupwardly on the chain or cable 3! attached to the latch member andtripping the same at the desired depth. The latch member having beentripped, either automatically by the trip rod 20 or manually by means ofthe chain or cable 3!, the thief tube with its sample is drawn up bymeans of the chain or cable 34 attached to the bail 33.

It will be noted that by the particular construction and arrangement ofparts hereinbefore set forth, a very simple, practical construction ofthief tube is afforded. The construction provides for securely wedgingthe closure in tight fitting engagement with the bottom of the tube orreceptacle to insure a liquid tight closure of the same. The specialclosure supporting and actuating means, and the particular latchmechanism are of a simple efficient nature and also of a character thatpermits of a close association of the same with the tube or receptacleto provide a compact structure.

What is claimed is:

1. A device of the class described, including a tube or receptacle openat top and bottom, a pair of arms pivotally connected to the tube orreceptacle at opposite sides thereof, a closure for the 7 lower end ofthe tube or receptacle carried by said arms for swinging movementtransversely of the bottom of tube or receptacle, means to force theclosure to closed position, a latch adapted to engage one of said armsfor holding the closure in open position, a pair of bearings on the tubeor receptacle arranged in spaced relation in longitudinal alignment, arod supported in said bearings to slide longitudinally and adapted toproject beyond the lower end of the tube or receptacle, said rod beingadapted to automatically trip the latch to release the closurewhen thelower end of the rod engages the bottom of a tank or the like, and apart on said rod between said pair of bearings adapted to cooperate withone of the same to limit the downward movement of the tube or receptaclerelatively to the rod.

2. A device of the class described, including a tube or receptacle openat top and bottom, a pair of arms pivotally connected to the tube orreceptacle at opposite sides thereof, a closure for the lower end of thetube or receptacle carried by said arms for swinging movementtransversely of the bottom of the tube or receptacle, a coiled springextending circumferentially of the tube or receptacle with its endsengaging said arms, the spring being adapted to force the closure toclosed position, a rod mounted on the tube or receptacle to slidelongitudinally and adapted to project beyond the lower end of the tubeor receptacle, and a latch on said rod adapted to engage the arms forholding the closure in open position, said rod being adapted toautomatically trip the latch to release the closure when the lower endof said rod engages the bottom of a tank or the like.

3. A device of the class described, including a tube or receptacle openat top and bottom, and having its lower end extending at an inclinationto the plane of the transverse axis thereof to provide a correspondinglyinclined seat for a closure,

a closure for the lower end of the tube or receptacle adapted to engagesaid seat, means pivoted at approximately the longitudinal axis of thereceptacle and at the side thereof supporting the closure for swingingmovement transversely of the bottom of the tube or receptacle around thehigher portion of the inclined closure seat and towards and from thelower portion thereof, the closure being connected to said supportingmeans for limited rocking movement relatively thereto, means to forcethe closure to closed position, the lower inclined end of the receptacleacting to cause the closure to be wedged tightly thereagainst when thesame is swung to closed position, and a latch for holding the closure inopen position adapted to be tripped to release the closure.

'ANNA B. BLAKE, Evecutria: of the Estate of James F. Blake,

Deceased.

